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BITSPilaniPilani Campus
Manufacturing Organization
and Management
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BITSPilaniPilani Campus
Materials HandlingLecture 10
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To manufacture any product, it is necessary either thatmaterials move from one step of the manufacturing
process to another or that operators move to the
materials.
The most common practice, of course, is to move thematerials.
This movement of materials from one processing area
to another and from department to department
necessitates the use of much personnel andequipment and the handling of tremendous tonnages
of materials.
Introduction
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Consideration for the handling of work-in-processesmaterials, as well as raw material and finished goods,has always been a part of the production systemsdesign process.
Basic cost accounting evaluation of the cost ofmanufacturing products reveals that when materialshandling costs are separated from other costs, theycan be seen to be significant.
Recently, the materials handling function has been
undergoing significant changes in concept andimplementation.
Introduction cont
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Management has been changing its view of materialshandling as the routine transfer of materials from place to
place and is beginning to think of it as part of a total
mater ials f low system.
This change in thinking has come about largely as a resultof new automatic handling and storage equipment and
systems that are integrated closely with automatic
processing and sophisticated management information
and control systems.
Materials handling is an integral part of facilities design.
The objective is to develop a layout which has a machine
or machining center configuration that will minimize the
materials handling effort.
Introduction cont
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In a broad sense, materials handling includes all movement ofmaterials, in a manufacturing situation. It has been defined bythe Materials Handling Division.
American Society of Mechanical Engineers, as follows:Materials handling is the art and science involving themoving, packing, and storing of substances in any form.
This is an all inclusive definition and can include fluids andsemi-fluids, as well as discrete items such as gears, tires,castings and boxes.
For the sake of simplicity, we shall limit our discussion in thischapter to the movement of discrete items, such as gears,
tires, castings, and boxes. Similarly, we shall consider onlythe movement of materials within the plant or storage areas.
Movement of materials between plants- particularly whencommon carriers are used is generally considered aproblem in traffic and is frequently handled by a separatetraffic department.
Definition of Materials Handling
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The simplest solution to the materials handlingproblem- Nomovement, no costis hardly practicablefor a complete manufacturing process.
It is basically sound approach when one is attempting
to improve a complete production cycle and when thenumber of handling can be reduced.
In the latter situation it is often more feasible to bringthe tools and workers to the product than to transportthe product to the machine or work area.
Objectives of Materials Handling
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In addition to the objective of reducing the overall costsof materials handling by reducing the number ofhandling involved, the following may be considered asobjectives of the engineer in his or her approach tothis problem.
Lower the uni t cost o f mater ials handl ing : If the overall materials handling costs are reduced the unit
costs will be reduced.
This approach requires the costs of handling be allocated to oridentified with the units of product, or it component parts that
are moved.A unit cost analysis may be very effective in determining which
handling involve excessive costs.
Objectives cont
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Reduce the manufactur ing cycle t ime: The total time required to make a product from the receipt of raw materials to the
finished goods can be reduced through effective materials handling.
Movement of materials can be speeded up or handled over shorter distances.
Successful reduction of the manufacturing cycle time will reduce inventory costsand other production costs incident thereto.
Contr ibute toward a better con trol of the f low o fgoods: A principle way in which good materials handling practice can effect savings is by
making the control of goods easier-particularly in continuous manufacturing,where all operations are tiedtogetherby the materials handling plan.
In this situation the problem of production control is reduced to control at the
starting point of the process and to the watching of the rate of flow at selectedcontrol points throughout the process.
In intermittent manufacturing, the integration of the materials handling plan with acomprehensive management information and control system can make a greatcontribution to the control of materials flow.
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Provide for improved work ing cond i t ions and greater safety inthe movement of mater ia ls: Many of the provisions of the occupational Safety and Health Act require
adherence to safe handling practices.
It is evident that the safe handling of material will be reflected in a betterindustrial accident record.
This is both a tangible saving in reduced insurance rates and an intangiblesaving in improved employee morale resulting from safer working conditions.
Provide for fewer rejects: Care in the handling of the product will contribute to a better quality level of the
goods produced.
Products damaged by inefficient handling are all too often a major cost tomanufacturer.
Achieve decreased storage requirement:
Better movement and storage of materials should increase the utilization ofstorage space.
Gain Higher produc t iv i ty at lower manufactur ing cost: Any materials handling system, if it is worth its investments, is design to improve
productivity.
This improvement should be achieved by moving materials in the fastest, mostefficient and economical way possible.
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A good materials handling engineer will generally have several yearsof experience that can be brought to bear on the solution of materials
handling problems or the design of materials handling systems.
While materials handling analysis is to a large extent an experience-
based endeavor, current increased availability of computers makes
material handling analysis susceptible to extensive mathematicalanalysis.
Where a strong quantitative analysis is not possible, a number of
guiding principles have evolved over the years to aid material handling
engineers in solving problems.
For many years, discussions of principles of materials handling have
been published by many experts in the field. The following list has
been adapted from two of these sources:
Principles of Material Handling
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1. Eliminate wasteful methods by Reducing to a minimum the number of handlings of
materials.
Eliminating unnecessary mixing and subsequent sorting.
Using mechanical aids to eliminate the use of hand laborin movement of materials.
Avoiding the unnecessary transfer of materials from floorto workplace or from container to container.
Increasing the speed of handling.
Utilizing containers and unit loads. Utilizing gravity as a moving force wherever practicable.
Introducing automatically into the materials handling plan.
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2. In laying out the plant: Plan a system for materials flow and combine handling withprocessing wherever possible.
Provide for continuous or appropriate intermittent flow ofmaterials.
Provide for the optimal flow of materials between operations
and with a minimum of retrograde movement. Plant the layout of the work-station area for a minimum of
handling of the product.
Maximize the quantity and size of weight handled.
Coordinate the overall materials handling throughout the entireplant.
Provide for safe handling and safe equipment and integratewith the management information and control system.
Plan for adequate receiving, storage and shipping facilities.
Make optimum use of building cubage.
Design adequate aisle and access areas.
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3. In the selection and application of materials
handling equipment:
Plan activities and analyze equipment needs before
considering the purchase of new equipment.
Ensure that the existing equipment is being used
effectively.
Use the simplest equipment that is adaptable to the
problem: avoid the use of complicated mechanisms and
controls. Adopt standard equipment if possible; ensure that the
purchase of special equipment is economically justified.
Select equipment that is flexible in its application.
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Select equipment that will minimize the ratio of mobileequipment deadweights to pay loads.
Determine comparative costs of equipment before
purchasing.
Recognize the need for different equipment for differentjobs.
Recognize the need to provide suitable building
conditions for the equipment.
Provide for alternative methods for use in emergencies.
Give consideration to the maintenance of the equipment.
Replace obsolete methods and equipment with more
efficient ones.
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It requires establishing an objective, collecting as muchfactual data as possible, analyzing the data, applying knownprinciples, and formulating a solution.
In collecting the data careful attention should be give to theeffect of handling on the product, the present method, and
cost factors. Hughes Aircraft described an example of the use of simulation
to study a materials handling problem.
They describe an effort to combine six storeroom into asingle, automated facility.
The simulation analysis enables the materials handling andprocess engineers to identify key interrelationships anddependencies that had to be considered in the new design.
Various simulation softwares: SLAM, SIMAN, SIMfactory
Analysis of Materials Handling
Problems
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Tompkins and White divide materials handlingequipment into five classifications. They give the
following list but note that numerous variations can
exist within each category:1. Conveyors
2. Monorails, hoists, and cranes
3. Industrial trucks
4. Containers and supports
5. Auxiliary and other equipment
General Types of Materials Handling
Equipment
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The selection of materials handling equipment requires
the attaining of proper balance between the production
problem, the capabilities of the equipment available, and
the human element involved.
The ultimate aim is to arrive at the lowest cost per unit ofmaterial handled.
Equipment factors to be taken into consideration may
well include the following:
Factors Affecting the selection of
Materials Handling Equipment
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Adaptability: The load carrying and movementcharacteristics of the equipment should fit the materialshandling problem.
Flexibility:Where possible the equipment should haveflexibility to handle more than one material, referring
either to class or size. Load capacity: Equipment selected should have great
enough load-carrying characteristics to do the jobeffectively, yet should not be too large and result inexcessive operating costs.
Power:Enough power should be available to do the job. Speed: Rapidity of movement of material, within the
limits of the production process or plant safety, should beconsidered
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Space requirements: The space required to install oroperate materials handling equipment is an important
factor in its selection.
Supervision required: As applied to equipment
selection, this refers to the degree of automaticitydesigned into the equipment.
Ease of maintenance: Equipment selected should be
easily maintained at reasonable cost.
Environment:Equipment selected must conform to anyenvironment regulations.
Cost:The consideration of the cost of the equipment is
an obvious factor in its selection.
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The cost of materials handling arises from two sources: the costof owning and maintaining equipment and the cost of operatingthe system.
General cost-accounting practice classifies the cost of handlingmaterials as an indirect cost or overhead.
This classification is based on the position that the movement ofthe materials does not contribute to their physical change or addvalue to them as a product or as a component part thereof.
In some manufacturing situations, such as a carbon black plantwhere the material is constantly moving during the production
process, this contention of the cost accountants might bechallenged.
However, the problem of classification of unit handling costs ofmost situations is more of an academic than a practical nature.
Accounting for Materials Handling
Costs
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The pattern of flow of materials in a plant definitely affectthe materials handling costs.
The production process should be so planned and themachines and benches so arranged that the handlings ofmaterials are reduced to a minimum with as little
backtracking of goods as possible. In the layout of a plant for continuous manufacture thepattern of flow is planned will in advance; because ofbalanced machine and assembly lines, it lends itself to awell planned flow of component parts, subassemblies, andassemblies.
This makes it possible to plant the handling of materials inadvance, procure and install the best equipment for the job,and design for a minimum materials handling cost.
However, one installed, the plan lacks flexibility- usually itcannot be changed without major expense.
Relation of Materials Handling to
Flow of Material and Plant Layout
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Material in storage is generally thought to be stationary oridle.
But the use of conveyors as storage devices is quitepopular.
These conveyors may be overhead and constantly
moving, yet utilizing ceiling space storage. Such an installation is pictured in figure 12-10. Otherstorage installations may be like the skate conveyorsshown in figure 12-11b.
In one Midwestern furniture plant the complete floor of the
finish drying room is covered by a large slat conveyor thatmoves very slowly: pieces placed on this floor at oneside of the room are dry when they reach the other side.
Storage
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Storage facilities and plants are closely related to the unitloading plan for the product.
It is very common to make use of high rise storage racks.
Permanent racks and bins may be eliminated in a
warehouse if goods are palletized in such a manner thatthe pallets can be stacked.
Stackable tote boxes and bins make the utilization of
storage space quite flexible.
To make maximum use of cubage, high rise, racksupported, totally dedicated buildings are increasing in
favor. In these building, the rack support both the roof and
the sidewalls and this greatly reduces the cost.
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Automatic storage and retrieval system (ASRS) whichfollows the painting operation at GM,s Saturn Division,
can store upto 900 complete sets, allowing the
manufacturer to sequence vehicles for assembly as the
stored components enter general assembly. Material handling and storage problems can be solved
jointly to the mutual advantage of both functions.
The common solution directly affects the layout of the
plant facilities or is itself influenced by the existing floorplan and building construction.
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Whether packaging is or is not a phase of materials handlingis to some degree an academic question. The unit load is initself a package.
Generally speaking, however, the term packaging is used tocover the preparation of the final product for shipment,particularly if the product is a consumer good.
From the viewpoint of a material handling problem, packagingof the incoming materials as well as of the outgoing productdirectly affect materials handling methods and equipment and the resultant materials handling costs.
The designing of the package of a product, although usuallyidentified as a separate activity or function, is closelyinterrelated with materials handling, methods of production,and marketing.
Attractively packaged good on the shelves and counters ofthe store, as well as the identification of large shipments ontrucks and railroad cars, are effective advertising and sales
promotion.
Packaging
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Modern packages are designed for efficient storage, notonly from the standpoint of rigidity for stacking but also for
effective protection of the product from the deterioration.
The use of plastic has contributed sound packaging. The
effect of some packaging materials such as Styrofoam isbeing addressed today in term of disposal.
Mechanization has important influence on the field of
packaging. Ex: food packaging, electric refrigerator.
Thus the package in which the material is handled is animportant part of the total materials handling problem in
manufacturing situation.
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Although the responsibilities and duties involved inmaterial handling must be necessary part of each
persons job, the coordination of the total materials
handling problem can be assigned to one person or
group. Large manufacturing organizations can well afford to
organize specialists in materials handling into one of
the staff advisory groups reporting to the manager of
manufacturing.
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Responsibilities assigned such a staff group may well include:1. Determining all new methods for the handling of new materials
or products and selecting the equipment to be utilized.
2. Conducting research in materials handling methods andequipment.
3. Conducting education and training for all manufacturingpersonnel in good material handling practices.
4. Establishing controls of current materials handling costs byanalysis of costs and comparison to budgets of either unit ortotal materials handling costs.
5. Initiating and conducting a continuing materials handling cost-
reduction or cost improvement program.6. Determining measurements for effectiveness of materials
handling that can become the yard sticks for progress in thisactivity.
7. Developing and conducting a preventive maintenance program
for all materials handling equipment.
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Thank You